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Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

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Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#31

Post by philipkglass »

icegreentea2 wrote: post #26
philipkglass wrote: post #6

Earlier quoted context omitted.

I would guess that even better than shipping ammonia or hydrogen to European steel plants would be to build new steel plants near the hydrogen producers, wherever they may be, and shipping iron ore there while shipping steel back out. Since iron ore and steel are much denser than either ammonia or hydrogen and do not need pressure vessels or chilling they can be shipped at lower speeds (save transport energy consumpt…

From this ( https://www.sciencedirect.com/science/article/pii/S095965261... ), they estimate a scaled up process requiring ~50kg of hydrogen to generate 1000kg of steel (which would be about 1500kg of iron ore). 50kg of hydrogen should be equivalent to like ~600kg of ammonia (if I did my math right). So there's a substantial mass difference in one way shipping of 600kg of ammonia versus two way shipping of ~1000kg of…

Thanks for the numbers! You and KMag have changed my mind. This is a lot less mass to ship around.

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#32

Post by Schroedingersat »

PaulHoule wrote: post #4
Robotbeat wrote: post #2

I don’t get this. We already use direct reduction using about half hydrogen, and that can be increased to over 90%. Producing ammonia via the Haber process means losing 40% or so of the energy (and potentially more as you convert it back), so why not just use hydrogen directly? Simply because moving hydrogen is harder than ammonia? I think it makes way more sense to just make and use the hydrogen on-site.

i think the question is how far you are shipping the hydrogen. If, say, people are making hydrogen in (say) the Middle East and shipping it to (say) Europe then the overhead of liquifying or compressing H2 is on the same order as converting to ammonia. In that paper they demonstrate that you can just use the ammonia directly to reduce iron and not have a separate system to convert it back. If you have a big wind powe…

>90% of the world's iron ore comes from very sunny places. Easier to just ship steel rather than iron ore and ammonia. For the last 10%, move the iron ore the other way (or still use local solar energy, because it is still cheaper than shipping ammonia).

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#33

Post by cyberax »

I don't get it. Why not just use methane?

It can be synthesized easily, we already have infrastructure to ship it around the world (just ask Putin for his opinion on that), and it's much less hazardous than ammonia.

Moreover, it doesn't require plants to switch to green methane right away. It can be done gradually and in a distributed fashion.

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#34

Post by bigger_cheese »

tonyarkles wrote: post #7
philipkglass wrote: post #6

Earlier quoted context omitted.

I would guess that even better than shipping ammonia or hydrogen to European steel plants would be to build new steel plants near the hydrogen producers, wherever they may be, and shipping iron ore there while shipping steel back out. Since iron ore and steel are much denser than either ammonia or hydrogen and do not need pressure vessels or chilling they can be shipped at lower speeds (save transport energy consumpt…

I'm asking this 100% from a place of curiosity because I don't know the answer. From iron ore to steel, how much waste is there? If the waste fraction is large, people might balk at the idea of either leaving that waste behind in the hydrogen-host country or burning fossil fuels to ship it around to have a carbon-free extraction process.

I work in the steel industry so can provide some info here.

In the mining of iron ore there is a step called "beneficiation" which involves the wet processing of minerals - this is not unique to iron ore and is common to many mining operations for a wide variety of materials, wet processing produces a waste slurry known as "tailings" which are typically stored in a dam or similar (https://en.wikipedia.org/wiki/Tailings_dam) - tailings dams have been the cause of major environmental issues in the past. Such as the Brazilian Dam failure in 2019 which killed 250+ people.

After beneficiation Iron ore is transported to a steelworks where it is smelted. The smelting process produces a further waste product "slag" (https://en.wikipedia.org/wiki/Slag) how much slag is generated depends on a few factors such as the efficiency of the plant and the quality of the raw materials. Steelmaking slags can have some further use, for example it can be used in the concrete and cement industry and as a road base but how much if any of it is recycled very much depends on the country and the steelworks in some countries, particularly those with looser environmental restrictions slag is sent to landfill.

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#37

Post by cyberax »

shagie wrote: post #29
eutectic wrote: post #14

What about electrolysis?

The question is "what is the most efficient way of getting hydrogen at the source?" Shipping it directly has problems with hydrogen being such a small gas and it is damaging to the vessel that it is transported in ( https://en.wikipedia.org/wiki/Hydrogen_embrittlement ). Pushing electricity to the source needs a lot of power to work on the scale of steel production. Generating electricity from further away means powe…

> The question is "what is the most efficient way of getting hydrogen at the source?"

Who said anything about hydrogen? You can directly reduce iron electrolytically: https://www.siderwin-spire.eu/

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#38

Post by 1letterunixname »

cyberax wrote: post #33

I don't get it. Why not just use methane? It can be synthesized easily, we already have infrastructure to ship it around the world (just ask Putin for his opinion on that), and it's much less hazardous than ammonia. Moreover, it doesn't require plants to switch to green methane right away. It can be done gradually and in a distributed fashion.

Drilling for methane adds GHGs to climate change.

For DRI, use a solar power tower to directly heat ore with "syngas" made similarly with solar heating and a renewable carbon source.

Such a setup can approach closed-loop production and emissions capture.

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#39

Post by TheSpiceIsLife »

boshomi wrote: post #18

Reduction of iron ore with carbon monoxid in closed loop: • Decarbonisation of BF-BOF through thermochemical closed carbon looping. • Demonstration of mass and energy flows of thermochemical BF-BOF system. • 88% emissions reduction of UK steel industry through £720 million investment. • Decarbonisation without retiring of existing BF-BOF, reducing stranded assets. • After 5 years, £1.28 billion savings and total UK-w…

The UK steel industry is 0.1% of the UK economy, at around 7 million tonnes per annum.

China producuces a little over 1 billion metric tonnes per annum

By what measure is this not futile?

Re: Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

#40

Post by iamerroragent »

cyberax wrote: post #37
shagie wrote: post #29

Earlier quoted context omitted.

The question is "what is the most efficient way of getting hydrogen at the source?" Shipping it directly has problems with hydrogen being such a small gas and it is damaging to the vessel that it is transported in ( https://en.wikipedia.org/wiki/Hydrogen_embrittlement ). Pushing electricity to the source needs a lot of power to work on the scale of steel production. Generating electricity from further away means powe…

> The question is "what is the most efficient way of getting hydrogen at the source?" Who said anything about hydrogen? You can directly reduce iron electrolytically: https://www.siderwin-spire.eu/

From article:

" Important examples are hydrogen-based direction reduction (HyDR),[4] hydrogen plasma smelting reduction,[5] and various electrolysis processes (e.g., molten oxides’ electrolysis,[6] molten salt electrolysis,[7] waster-assisted molten salt electrochemical reduction,[8] and electrowinning of solid iron from aqueous solutions[9]). Among these alternatives, the HyDR approach has today reached the highest technology readiness level (TRL 6–8) and is currently being deployed at industrial scale.[2, 10] In this process, green hydrogen should be ideally used, i.e., hydrogen that has been produced using renewable energy sources, generating water instead of carbon dioxide as redox product.[4]

"

This article is trying to make HyDR more green since it's already deployed more at an industrial level compared to alternatives at the moment.

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